Objective: To analyze embryos after in vitro maturation by investigating their nuclear status and cytogenetic constitution.
Design: Prospective randomized laboratory study.
Setting: Reproductive medicine unit in an academic hospital.
Patient(s): Patients with male and tubal factor infertility undergoing fertility treatment.
Intervention(s): Denuded immature oocytes (n = 75) were matured in vitro for 24–30 hours, and intracytoplasmic sperm injection was performed 30 hours after oocyte retrieval. Fluorescence in situ hybridization was performed on the produced embryos.
Main Outcome Measure(s): Blastomere content of the total embryo.
Result(s): The in vitro–matured oocytes showed a similar fertilization rate as the in vivo–matured oocytes, but with a higher incidence of noncleavage (21.0%). In addition, 26.7% of these embryos arrested at the first mitotic division. Thirty embryos were processed for fluorescence in situ hybridization; only 6.7% had all mononuclear blastomeres, 30.0% had at least one binuclear blastomere, 43.3% had at least one multinuclear blastomere, and 56.6% contained anuclear cells. The chromosomal constitution was analyzed in 14 embryos, and chromosomal anomalies were found in 11 (78.5%).
Conclusion(s): Germinal vesicle oocytes retrieved from superovulated patients and cultured in vitro for a short time had the ability to resume meiosis and achieve fertilization. However, arrest of embryo development was common. These embryos showed a high incidence of multinuclear blastomeres and aneuploidy, suggesting abnormal cytokinesis or genetic abnormalities.
